Disposable wearing article

Abstract

A disposable wearing includes a crotch chassis having a liquid-impervious sheet. The crotch chassis has a main region and opposite lateral portions lying outboard of the main region in the transverse direction and provided with leg elastic elements extending in the longitudinal direction. The opposite lateral portions respectively have fold lines extending in the longitudinal direction, outer side zones lying outboard of the respective fold lines in the transverse direction and inner side zones lying inboard of the respective fold lines in the transverse direction. The outer side zones of the respective lateral portions are folded inward and fixed to the associated inner side zones via associated bond zones extending in the longitudinal direction to form a pair of elastic lateral portions having folded back regions, respectively.

The invention claimed is: 
     
       1. A disposable wearing article having a longitudinal direction, a transverse direction extending orthogonally to the longitudinal direction, said disposable wearing article comprising:
 a skin-facing side; 
 a non-skin-facing side; 
 a front waist region; 
 a rear waist region; and 
 a crotch region extending between the front and rear waist regions, and including an elastic waist panel defining the front and rear waist regions and a crotch chassis attached to the elastic waist panel to define respective portions of the front and rear waist regions and the crotch region, 
 wherein 
 the crotch chassis includes a liquid-impervious sheet having a main region and opposite lateral portions lying outboard of the main region in the transverse direction and provided with leg elastic elements extending in the longitudinal direction, 
 the opposite lateral portions respectively have
 fold lines extending in the longitudinal direction, 
 outer side zones lying outboard of the respective fold lines in the transverse direction and 
 inner side zones lying inboard of the respective fold lines in the transverse direction, 
 
 the outer side zones of the respective lateral portions are folded back inward and fixed to the associated inner side zones via associated bond zones extending in the longitudinal direction to form a pair of elastic lateral portions having folded back regions, respectively, 
 the leg elastic elements include first leg elastic elements extending in the longitudinal direction and second leg elastic elements curving convexly inward, and 
 outer side edges of the respective folded back regions are shaped so as to curve concavely outward along the second leg elastic elements. 
 
     
     
       2. The wearing article defined by  claim 1 , wherein
 the liquid-impervious sheet is a laminated crotch sheet including an inner crotch sheet lying on the skin-facing side and an outer crotch sheet lying on the non-skin-facing side, and 
 the leg elastic elements are strand- or string-shaped leg elastic elements interposed between the inner and outer crotch sheets. 
 
     
     
       3. The wearing article defined by  claim 2 , wherein at least one of the inner and outer crotch sheets is formed of a thermoplastic resin film. 
     
     
       4. The wearing article defined by  claim 2 , wherein
 the pair of the elastic lateral portions is formed by bonding the outer side zones and the inner side zones of the respective lateral portions via
 lateral bond zones extending in the longitudinal direction, and 
 end segment bond zones extending along opposite end segments of the respective lateral portions in the transverse direction, 
 
 of the inner and outer crotch sheets, at least the inner crotch sheet is formed of a thermoplastic resin film, and 
 surfaces to be bonded in the lateral bond zones and the end segment bond zones are formed of a thermoplastic resin film. 
 
     
     
       5. The wearing article defined by  claim 1 , wherein the pair of the elastic lateral portions is formed by bonding the outer side zones and the inner side zones of the respective lateral portions via
 lateral bond zones extending in the longitudinal direction, and 
 end segment bond zones extending along opposite end segments of the respective lateral portions in the transverse direction. 
 
     
     
       6. The wearing article defined by  claim 5 , wherein the lateral bond zones respective lie outboard of the respective leg elastic elements in the transverse direction at least in a midsection of the crotch region. 
     
     
       7. The wearing article defined by  claim 5 , wherein the lateral bond zones are spaced from the associated outer side edges of the respective folded back regions and surround the associated outer side edges. 
     
     
       8. The wearing article defined by  claim 1 , wherein the inner side zones and the outer side zones of the respective lateral portions are bonded together via the associated bond zones and then partially folding the respective outer side zones outward in the transverse direction to form respective folded zones which are, in turn, bonded to the associated inner side zones via flap bond zones. 
     
     
       9. The wearing article defined by  claim 1 , wherein the main region of the crotch chassis is provided on the skin-facing side with a sheet-shaped bodily fluid absorbent structure comprising superabsorbent polymer particles wrapped with a liquid-pervious sheet. 
     
     
       10. The wearing article defined by  claim 1 , wherein the folded back regions are fixed to both the lateral portions of the liquid-impervious sheet by bond zones.